This research will assess the impact of changes in male and female economic opportunity on marriage formation in the United States since 1960. The rise in median age at first marriage over the past four decades is one of the most dramatic and consequential demographic shifts in American history. Initially, most analysts ascribed the change to rising economic opportunity and employment of women. More recently, however, demographic researchers have focused on men, contending that stagnant or declining male economic opportunity in the 1970s and 1980s contributed to the unprecedented delay in marriage by reducing the supply of marriageable men. This project will test the hypothesis that changes in both male and female economic opportunity affected the shift in marriage formation. In particular, the study will test whether the relationship between female opportunity and marriage formation has evolved since 1960. According to the hypothesis, rising female opportunity discouraged marriage, but that effect diminished over time;after 1970, the decline in the supply of young men with good jobs was increasingly associated with late marriage. The central aim is to assess historical changes in the effects of changing male and female opportunity simultaneously. Multi-level analysis will be used to assess the relationship between local economic conditions-measured as wage distributions and labor-force participation-and the marriage decisions of young men and women. The analyses will include separate models by gender, race, and ethnicity. This study will capitalize on a vast new archive of restricted-access long-form census data currently in preparation by the Census Bureau in collaboration with the Minnesota Population Center (IPUMS Redesign, NIH R01- HD43392). This data series includes the complete long-form census returns for the period from 1960 to 2000. The work is directly relevant to the mission of the NIH as the steward of medical and behavioral research for the nation: the changes in marriage behavior have direct and profound implications for the health and well-being of American adults and children.